The present invention relation to embedded type speaker units mountable by being embedded in an opening section formed in a mounting part, such as a ceiling or side wall.
There have heretofore been known embedded type speaker units (such as ceiling speakers) that are installed or mounted by being embedded in an opening section formed in a ceiling or the like of a room, as disclosed for example in Japanese Patent Application Laid-open Publication No. 2014-017810 (hereinafter referred to as “the relevant patent literature”). Generally, such speaker units include a cabinet section of a substantially cylindrical shape, and a speaker face provided in the bottom surface of the cabinet section. To mount the speaker unit to a ceiling, for example, the cabinet section is inserted into a mounting hole (opening section) of the ceiling with the speaker face exposed on the face (i.e., lower surface) of the ceiling, and then the inserted cabinet section is fixed or fastened to the ceiling by fastening via bolts or the like. A mounting structure for such a speaker unit includes a provisionally fastening mechanism for preventing the heavy speaker unit from falling down accidentally or by mistake before the fastening via the bolts or the like or after cancellation of the fastening, as disclosed in the relevant patent literature.
When the speaker unit is to be dismounted from the opening section of a ceiling or the like for maintenance or replacement purpose, there arises a need to cancel the provisional fastening, with respect to the mounting hole, of all of the provisionally fastening mechanisms. However, with the provisional fastening mechanisms disclosed in the relevant patent literature, each of which is constructed to be operated laterally from a side-surface side, not from a speaker-surface side (i.e., face side), a human operator cannot view the provisional fastening mechanism from the speaker-surface side. Thus, at the time of maintenance, for example, the human operator has to grope for (i.e., feel for or find with a hand alone) the position of the speaker-surface side, so that operation for canceling the provisional fastening would undesirably take much time and labor. Further, to dismount the speaker unit from the provisionally fastened position, the human operator has to cancel the provisional fastening of the speaker unit by inserting, from a lateral side, his or her finger into a gap between the speaker unit and the ceiling. However, if the ceiling plate has a great thickness, the finger cannot be inserted deep enough into the gap between the speaker unit and the ceiling because the gap is too narrow even in the provisionally fastened state, which would result in the problem that manipulation or operation of the provisional fastening mechanism is difficult to perform.